Consumers of fibrous structures, especially paper towels, require absorbency properties (such as absorption capacity and/or rate of absorption) in their fibrous structures. The pore volume distribution present in the fibrous structures impacts the absorbency properties of the fibrous structures. In the past, some fibrous structures exhibit pore volume distributions that optimize the absorption capacity others exhibit pore volume distributions that optimize the rate of absorption. To date, no known fibrous structures balance the properties of absorption capacity with rate of absorption and surface drying via the pore volume distribution exhibited by the fibrous structures.
Known fibrous structures exhibit various pore volume distributions. For example, a currently marketed wood pulp-based paper towel exhibits a substantially uniform pore volume distribution. In another example, a currently marketed wipe product has significantly more than 55% of its total pore volume present in the wipe product that exists in pores of radii of less than 100 μm. In yet another example, a currently marketed non-textile washcloth has significantly more than 55% of its total pore volume present in the wipe product that exists in pores of radii of greater than 200 μm.
The problem faced by formulators is how to produce fibrous structures that have a pore volume distribution that balances the absorbency properties (i.e., absorption capacity and rate of absorption and surface drying) that satisfies the consumers' needs.
Accordingly, there is a need for fibrous structures that exhibit a pore volume distribution such that at least 25% and/or at least 43% of the total pore volume present in the fibrous structures exists in pores of radii of from 91 μm to about 140 μm, and for methods for making such fibrous structures.